1. Field of the Invention
The invention is directed to a mechanism for directing the low grain/high chaff mixture from the separating assembly to a precleaner before introducing this mixture to the chaffer of the cleaning shoe. The high grain/low chaff mixture from the threshing section is introduced to the upstream end of the chaffer, whereas the precleaner introduces the precleaned chaff rich mixture to the chaffer downstream from where the grain rich mixture is introduced.
2. Description of the Prior Art
Typically, a high grain/low chaff mixture from the threshing section is mixed with a low grain/high chaff mixture from the separating section. These combined mixtures are directed to the cleaning assembly for removing the chaff from the grain. In most combines, the cleaning assembly comprises three major components: a cleaning fan, a chaffer and a sieve. The cleaning fan has its own housing, whereas the chaffer and sieve are mounted to the cleaning shoe.
The cleaning fan is a multi-bladed fan located in front of the cleaning shoe. The air blast from the fan removes most of the chaff and straw from the grain by blowing it out the rear of the combine.
The cleaning shoe, which contains the chaffer and sieve, is mounted to the supporting structure of the combine below the separating assembly. The bottom of the cleaning shoe contains the tailings auger and the clean grain auger.
The chaffer and sieve are suspended on hangers attached to the sides of the cleaning shoe. There are three types of typical shoe action, reciprocating, shaking and cascading. In the reciprocating shoe the chaffer and sieve move in opposite directions to one another. In the shaking shoe the chaffer and the sieve move in the same direction. In the cascading shoe the chaffer and sieve are arranged so that the material drops from one unit to another in a cascading or rolling motion.